CHICAGO — Brown Bag Seafood Co. will open its newest location in Willis Tower. The fast-casual seafood concept will be located in Catalog, the 300,000-square-foot dining and retail area at the base of the office tower. Catalog is currently under construction. Willis Tower is undergoing a $500 million renovation project, the biggest transformation in the building’s 46-year history. The first phase is expected to be open to the public in late 2019. Brown Bag Seafood Co. joins Convene, Urbanspace, Shake Shack, Sweetgreen, Starbucks and Market Creations. The Willis Tower location will be Brown Bag’s sixth restaurant. Willis Tower, formerly Sears Tower, is a 110-story skyscraper and is the tallest building in Chicago.